1. Field of the Invention
The present invention generally relates to a non-floating vertical transistor and a method to form a non-floating vertical transistor. In particular, the present invention is directed to a non-floating vertical transistor structure which has segregating pillars to electrically segregate word-lines and a method to form the non-floating vertical transistor structure.
2. Description of the Prior Art
A gate is a core element in a semiconductor device and in charge of switching on or switching off the electrical current between the source and the drain in the semiconductor device. When an appropriate voltage is applied on the gate, the channel for the electrical current between the source and the drain is opened. The minimum voltage for opening the channel is called the threshold voltage (VT). Due to the internal capacitance in the semiconductor device, the floating body effect results in the problem of VT shift and jeopardizes the operation of the semiconductor device.
Accordingly, a novel semiconductor structure is still needed to overcome the problem of VT shift which is caused by the floating body effect and to correct the abnormal operation of the semiconductor device caused by the VT shift problem.